8 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



GLOBIGERINA DUBIA Egger. 



Plate 2, figs. 6-8. 



Globigerina dubia Egger, Neues Jahrb. fur Min., 1857, p. 281, pi. 9, figs. 

 7-9.— H. B. Brady, Quart. Journ. Micr. Sci., vol. 19, 1879, p. 71; Rep. 

 Voy. Challenger, Zoology, vol. 9, 1884, p. 595, pi. 79, figs. 17 a-c. — 

 Egger, Abh. kon. bay. Akad. Wiss. Miinchen, CI. II, vol. 18, 1893, p. 

 366, p. 13, figs. 36-38, 77. — Chapman, Proc. Zool. Soc. London,- pt. 1, 

 1895, pi. 37.— Goes, Bull. Mus. Comp. Zool., vol. 29, 1896, p. 66.— 

 Flint, Rep. U. S. Nat. Mus., 1897 (1899), p. 322, pi. 69, fig. 4.— Rhum- 

 BLER, in Brandt, Nordisches Plankton, Heft. 14, 1900, p. 19, fig. 20.— 

 Chapman, Journ. Linn. Soc. Zool., vol. 28, 1901, p. 404. — Bagg, Proc. 

 U. S. Nat. Mus., vol.- 34, 1908, p. 154. — Chapman, Journ. Linn. Soc. 

 Zool., vol. 30, 1910, p. 417.— Bagg, Bull. 513, U. S. Geol. Survey, 1912, 

 p. 79, pi. 22, figs. 4 a-d. — Chapman, Zool. Res. "Endeavour," pt. 3, 

 1912, p. 311.— CusHMAN, Bull. 71, U. S. Nat. Mus., pt. 4, 1914, p. 6, pi. 

 4, figs. 1 — 3.— Pearcey, Trans. Roy. Soc. Edinb., vol. 49, 1914, p. 

 1025.— Chapman, BioL Res. "Endeavour," vol. 3, pt. 1, 1915, p. 26.— 

 Heron-Allen and Earland, Trans. Zool. Soc. London, vol. 20, 1915, 

 p. 678; Trans. Linn. Soc. London, ser. 2, vol. 11, 1916, p. 267.— Mes- 

 TAYER, Trans. New Zealand Inst., vol. 48, 1916, p. 129. — Sidebottom, 

 Journ. Roy. Micr. Soc, 1918, p. 149.— Cushman, Bull. 103, U. S. Nat . 

 Mus., 1918, p. 65; Proc. U. S. Nat. Mus., vol. 56, 1919, p. 621. 



Description. — Test composed of numerous inflated chambers 

 arranged in a nautiloid spiral; chambers all visible from above, 

 umbilicate below, with only the chambers of the last volution visible, 

 usually 5 to 6 in number; wall reticulate; apertures of the chambers 

 opening into the umbilical cavity. 



Diameter, 0.50-0.80 mm. 



Distribution. — From the records G. dubia is a very widely dis- 

 tributed species. That more than one species may be passing under 

 this name is a very evident conclusion from the study of published 

 figures. I have placed under it here three or four forms which may 

 later prove to be distinct. In the Gulf of Mexico there are specimens 

 with a rather high test and a deep umbilical region very different from 

 the ordinary form of the species. Such forms may later be found to be 

 distinct. In other parts of the area also there seem to be varietal 

 forms which need further study before a final disposition of them can 

 be made. This must be left to future dredgings. 



Especially in such species as this where the original specimens were 

 fossil ones a study of the type material is necessary to make clear 

 just what the author had in mind and whether this should apply to 

 so great a mass of recent material from many regions. 



GLOBIGERINA SUBCRETACEA Chapman. 



Under this name Chapman has placed the recent species which 

 has been referred by many authors as Globigerina cretacea. It is 

 probable that the recent species is not the same as the Cretaceous 

 one. In the Albatross material I have not attempted to dist'.guish 

 this from G. dubia Egger. 



